US 7314568 B2
A multi-stage water conditioning system is structured for conditioning a flow of influent water passing through the conditioning system by removing one or more cations including sodium, iron, barium, and or ammonia from the influent water, while also possibly adding (as required) calcium and magnesium. Such a conditioning of the influent water results in a reduction in the sodium adsorption ration (SAR) and electrical conductance (EC) of the influent. Versions of the water conditioning system may include a surge and equalization stage, and at least one conditioning stage, which is typically followed by an output finishing stage. Each included conditioning stage provides for a contacting of the influent water with surfaces of a load of molecular filtering material causing a reduction in sodium and other cations as the influent waters flow through the water conditioning system. The system further provides for the inclusion of a regeneration mechanism that is included for regenerating each load of molecular filtering material of each conditioning stage when the molecular filtering material becomes saturated with cations such as sodium, barium, and iron, which have been removed from influent water being conditioned.
1. A method for conditioning a volume of influent water resulting from coal bed methane drilling activities, with the conditioning employed to reduce the electrical conductance of the influent water by reducing levels of sodium cations and bicarbonates present in the influent water, with the method comprising the steps of:
a) preparing and chemically modifying a load of molecular filtering material for use in a process stage for conditioning influent water passing through the process stage by way of an ion exchange process;
b) collecting influent water and employing a gravity feed arrangement for causing a flowing of the influent water through the process stage, wherein the influent water enters at a lower location proximate to a bottom of the process stage, thereby causing the influent water to flow upwardly through the load of molecular filtering material, while exiting the process stage at a location that is proximate to a high water line and elevated with respect to the lower location proximate to the bottom at which the influent water first entered the process stage;
c) with the flowing of the influent water through the process stage effecting a contacting with surfaces of the load of molecular filtering material and causing a cation exchange process wherein sodium cations are exchanged while calcium cations and bicarbonates are released;
d) further employing the gravity feed arrangement for causing a flowing of partially conditioned influent water from the process stage into an output finishing stage, for additional conditioning wherein the calcium cations now present in the influent water react with bicarbonates, causing a precipitating of the bicarbonates as the partially conditioned influent water passes through the output finishing stage, prior to exiting from the output finishing stage;
e) with the conditioning of the volume of influent water resulting from coal bed methane drilling activities, wherein the gravity feed arrangement is employed for causing a flowing and conditioning of the influent water for reducing the electrical conductance by reducing levels of sodium cations and bicarbonates present in discharged output water.
2. The conditioning method as recited in
3. The conditioning method as recited in
a) suspending the flow of influent water entering a process stage to be regenerated;
b) causing a volume of regeneration chemicals to contact the load of molecular filtering material of the process stage for a pre-determined time interval until the load of molecular filtering material has been regenerated;
c) pumping a salt brine produced by the regenerating step from the process stage;
d) rinsing the load of molecular filtering material of the process stage with fresh water;
e) re-establishing the flow of influent water through the regenerated molecular filtering material of the process stage, thereby resuming the conditioning of influent water.
4. The conditioning method as recited in
5. The conditioning method as recited in
6. A method for conditioning a volume of influent water resulting from coal bed methane drilling activities, with the conditioning of the volume of influent water resulting in a reducing of electrical conductance of the influent water by reducing levels of sodium cations and bicarbonates present in the influent water, with the method comprising the steps of:
a) preparing and chemically modifying at least one load of molecular filtering material for use in at least one process stage for conditioning influent water passing through each process stage;
b) employing a gravity feed arrangement for causing a flowing of influent water through each included process stage wherein the influent water contacts surfaces of the load of molecular filtering material causing a cation exchange process wherein sodium cations are adsorbed while calcium cations are released;
c) coupling a flow of partially conditioned influent water exiting at least one process stage into an output finishing stage for additional conditioning wherein the calcium cations added to the influent water when passing through the process stage react with bicarbonates present in the water that were released during the cation exchange process of the earlier process stage, causing a precipitating of calcium bicarbonate;
d) thereby providing a conditioning method wherein by-products of an initial first stage conditioning, including calcium cations and bicarbonates, which flow into the output finishing stage causing a precipitating of calcium bicarbonate, which in turn lowers the electrical conductance of the coal bed methane influent waters, enabling the resulting output water flowing from the output finishing stage to be directly discharged into the environment.
7. The method for conditioning a volume of influent water as recited in
8. The method for conditioning a volume of influent water as recited in
9. The method for conditioning a volume of influent water as recited in
10. The method for conditioning a volume of influent water as recited in with
11. The method for conditioning a volume of influent water as recited in
The subject matter contained herein is related to provisional patent application Ser. No. 60/526,152 filed on Dec. 1, 2003, which is hereby incorporated by reference.
The present invention relates most generally to water processing, conditioning, and/or treatment systems. More particularly, the invention relates to substantially passive means and methods for conditioning a volume of influent water having high concentrations of sodium, soluble salts, and or other cations, in order to produce a volume of conditioned output water that has a significantly reduced salt load (SL), electrical conductance (EC), and sodium adsorption ratio (SAR).
A variety of known activities produce as a by-product discharge waters that must be disposed of in an environmentally safe and acceptable fashion. Often these discharge waters must be processed in such a manner wherein they can be utilized for other uses, such as irrigation, or simply released into a proximate stream or river. It may be noted that the discharge waters with which the present invention may be employed are to be broadly defined, and may certainly originate from natural sources, man-made sources, or a combination of both.
An interesting example wherein discharge waters are produced as a side product that may be processed and conditioned by the present invention may be found in coal-bed methane drilling. The United States coal-bed methane (CBM) industry is developing at a rapid pace filling a significant need for methane (natural gas). Very often the pockets of methane are trapped in deep coal seams by water in the coal. Drilling into a coal seam results in a releasing to the surface of the CBM water, freeing the methane for collection and subsequent distribution. The CBM water, which may be additionally termed ‘discharge water’ or ‘influent water’, is typically characterized as being high in sodium, soluble salts, and/or other cations. For example, sodium concentrations can often be in excess of 1000 mg/l. In addition, the ratio of sodium to calcium and or magnesium, which is defined as the Sodium Adsorption Ration (SAR) is often in excess of 30 or more. Another measure of interest is electrical conductance (EC), which for CBM discharge waters may exceed 4500 micromhos/l. Each of these levels is considered quite high, and in each case will often prevent a direct and legal releasing of the discharge water into the environment. A simple releasing of these waters is typically not permitted by Federal and or State regulations for several reasons. First, waters with high concentrations of soluble salts are toxic to many plants. Additionally, sodium causes the dispersing of clay, which may cause top soil to be eroded (e.g., by wind and rain), and also reduces water and air permeability of soils.
Accordingly, at the present time industry and regulatory agencies are searching for means and methods for cost-effectively processing and conditioning waters, such as CBM discharge waters. There is clearly a need for new and improved systems and associated methods for conditioning waters such as CBM discharge waters that are high in sodium, soluble salts, and other cations, in a relatively simple and cost effective manner. The conditioned ‘output water’ that flows from systems employing the present invention will preferably be of such a quality that the water can be used for purposes such as irrigation and live stock watering, or alternately simply released into the environment (e.g., into a proximate stream or river). Importantly, it may be noted that the discharge water to be conditioned in accordance with the present invention will be termed ‘influent water’, which enters and flows through an embodiment of the present invention for conditioning purposes.
A number of other additional characteristics, advantages, and or associated novel features of the present invention, will become clear from the description and figures provided herein. Attention is called to the fact, however, that the drawings are illustrative only. In particular, the embodiments included and described, have been chosen in order to best explain the principles, features, and characteristics of the invention, and its practical application, to thereby enable skilled persons to best utilize the invention and a wide variety of embodiments providable that are based on these principles, features, and characteristics. Accordingly, all equivalent variations possible are contemplated as being part of the invention, limited only by the scope of the appended claims.
In accordance with the present invention, a multi-stage water conditioning system is structured for removing, at minimum, one of sodium and soluble salts from a supply of influent water to be conditioned. In addition, preferred embodiments of water conditioning systems will also condition influent water by removing one or more of iron, barium, ammonia, potassium, while adding (as required) calcium and magnesium.
Preferred embodiments may be structured with a plurality of what may be broadly termed ‘conditioning stages’ or ‘process stages’. For example, a most preferred embodiment of the invention will include at least one conditioning stage configured with a load of a molecular filtering material arranged such that the flowing of the influent water through such a stage causes the reduction of at least one of salt load, sodium concentration, and other cations including one or more of iron and barium. Accordingly, the electrical conductance (EC) of the influent is lowered as the influent flows through each provided volume of molecular filtering material of each process stage.
As will be discussed further hereinafter, each conditioning stage is preferably structured such that influent water enters at a lower location proximate to a bed or bottom region of the conditioning stage and flows upwardly. Upon flowing through the molecular filtering material, and contacting surfaces thereof, the (at least partially conditioned) influent water exits at an upper location. This arrangement, which causes an upflowing of the influent water when flowing through a conditioning stage, has been found to provide the most uniform flow characteristics—thereby causing a maximizing of contacting of the surfaces of the molecular filtering material by the influent water.
In addition, to each conditioning stage structured with a load of molecular filtering material, most preferred embodiments of the invention further include an output finishing stage. The output finishing stage is arranged to receive influent water exiting a conditioning stage to provide for a further reducing of at least one of salt load, sodium concentration, and electrical conductance, while also further reducing the SAR ratio of sodium to other cations such as calcium and magnesium. It is contemplated that one or more mechanisms may be included with the output finishing stage. For example, a chemical drip mechanism, for applying one or more chemicals, may be provided for causing a precipitating of bicarbonates, and possibly other anions and cations. Chemicals of interest for this purpose may include one or more of a selected acid, a calcium containing chemical such as calcium oxide, and a magnesium containing chemical such as magnesium oxide. In addition, automated mechanisms may be included for controlling the drip rate of each included chemical, preferably in a closed loop fashion. Yet other mechanisms may be included with the output finishing stage, for example, aeration and dispersing mechanisms.
Another important aspect of the present invention calls for the inclusion of a regeneration mechanism. A suitable regeneration mechanism provides for the periodic “regenerating” of the load of molecular filtering material in at least one included conditioning stage. Regeneration becomes necessary when the molecular filtering material becomes saturated with sodium, barium, iron, as well as other cations, which have been removed from influent water being conditioned. In most preferred embodiments of the present invention a regeneration mechanism is coupled to each conditioning stage containing a load of molecular filtering material.
Regeneration may be effected by contacting the load of molecular filtering material therein with regeneration chemicals for a selected interval of time, as required. Typically, once the molecular filtering material is contacted with one or more chemicals of the regeneration mechanism, a heavy salt brine is produced and drained. Next, the load of molecular filtering 4 material will most preferably be flushed by way of one to three ‘rinse cycles’. The preferred regeneration chemicals and structures will be discussed in greater detail hereinafter.
Another aspect of the present invention includes a surge and equalization stage. For example, the influent water may be first collected and held for a period of time in a surge and equalization pond before flowing into a first conditioning stage. As such, a surge and equalization stage may be included having at least one input coupled to an influent water source, and at least one output coupling the flow of influent water from the surge and equalization pond to the first process stage for contacting the surfaces of the molecular filtering material therein. In the most preferred embodiments of the surge and equalization stage a vessel (e.g., a large earthen pond) may have a sufficient capacity for holding a pre-determined volume of influent water such that the flow of influent water from the surge and equalization pond to the first process stage may be suspended, for a period of time, as required for servicing and regenerating at least one conditioning stage thereof.
In the drawings, like elements are assigned like reference numerals. The drawings are not necessarily to scale, with the emphasis instead placed upon the principles of the present invention. Additionally, each of the embodiments depicted are but one of a number of possible arrangements utilizing the fundamental concepts of the present invention. The drawings are briefly described as follows:
It is important to establish the definition of a number of descriptive terms and expressions that will be used throughout this disclosure. The terms ‘conditioning’, ‘water conditioning’, and equivalents, as applied to embodiments of the water conditioning system taught herein, are to be understood to result in an altering of actual levels or relative levels (e.g. ratios) of cations and possibly anions to levels wherein the conditioned influent water may be simply discharged to the environment or employed for irrigation. For example, properly employing preferred embodiments of the invention will result in a reduction in the sodium adsorption ration (SAR) of the conditioned influent water, while also lowering the salt load (SL) and electrical conductance (EC). The term ‘molecular filtering material’ is to be understood to be any material, typically provided in a granular or powdered form, that can aid in producing the desired conditioning results (e.g., a reduction in SAR, EC, etc.). Preferred molecular filtering materials include one or more available zeolite materials. The terms ‘reducing’, ‘reduced’, and ‘lowered’, are important terms employed when describing the conditioning of influent water flowing through the water conditioning system of the present invention. Specific reductions attained with the invention will vary with a number of parameters, including the type of molecular filtering material employed, the cation and anion types and levels present in the influent water to be conditioned, the flow rate through the system, the number of conditioning and finishing stages utilized, etc. As such, the actual amount of reducing or lowering of levels of cations and anions realized may vary considerably with differing embodiments and constructions of the invention, as well as the actual influent to be conditioned. The terms ‘coupled’, ‘coupled to’, etc., are to be understood to mean that two items are either directly connected, or alternately, connected to each other via one or more additional (possibly implied or inherent) structures or components. The terms ‘fluidically coupled’ and ‘fluidic coupling’ are to be defined as the necessary conduits, couplings, tubings, pipes, etc., which may be employed to draw and or deliver influent water from a first location to a second location. Other important terms and definitions will be provided, as they are needed, to properly define the present invention and its associated novel characteristics and features.
Referring now to the drawings,
As indicated in
Each of these functions will now be concisely discussed for completeness. As understood by skilled persons, the above functions of the surge and equalization stage may prove critical in certain applications. For example, when considering the conditioning of influent water in the form of coal-bed methane (CBM) discharge waters, a surge and equalization stage is typically required as the flow of CBM waters is not constant and predicable, and can vary from a few gallons a minute to several hundred gallons a minute, or more. As such, surge control may be an important consideration. In addition, influent waters such as CBM discharge waters often require a period of time for equalization of chemical quality (e.g., homogeneity). As such, a minimal retention time of the influent waters within the surge and equalization stage before flowing into a first conditioning stage is an important consideration. Finally, preferred embodiments of the surge and equalization stage 16 are to be provided with a sufficient capacity to be able to store a flow of influent waters 18 a for a period of time during which regeneration of one or more volumes of molecular filtering material of a process stage may be effected. As indicated hereinabove, the regeneration of molecular filtering material is required when the molecular filtering material becomes saturated with cations that have been removed from influent water being conditioned by contacting the molecular filtering material.
As illustrated in
As further indicated in
As will be discussed hereinafter, preferred regeneration methods typically require a suspending of the flowing of influent water through the conditioning or process stage to be regenerated. Once regeneration has been completed the regenerated process or conditioning stage is again available for effectively removing cations and lowering the SAR and EC levels of influent water flowing through the regenerated stage.
As shown in
Turning again to
Referring now to
After flowing through each conditioning bed included with an embodiment of the invention, an influent water flow 18 e flows from an output of the last conditioning stage, which for the embodiment of
Returning again to
The use of each of these valves, as well as other valve arrangements providable by skilled person, will more completely discussed when referring to
When considering water conditioning systems that are of such a scale wherein hundreds of gallons of influent water can be conditioned per minute, embodiments such as that of
In addition, to the above listed preferences, each earthen constructed stage/pond is most preferably lined with at least one of a high density polyethylene (HDPE) or polyproylene sheet/liner material. As skilled individuals will appreciate, a liner of such material having a thickness of 25 to 50 mils will provide a low cost, long life water conditioning system in accordance with the invention. For example, when considering a most preferred embodiment of the invention, such as depicted in
Although earthen constructed ponds and vessels may be most cost effective for large water conditioning systems of the invention, containers and vessels employed for each stage may certainly be constructed of a variety of suitable materials including plastic, steel, and or concrete.
Referring now to
As appreciated by skilled individuals, a multi-channel embodiment such as 10 b of
Alternatively, a multi-channel embodiment can be employed such that water conditioning may be effected substantially by a first channel, such as channel CH-A, while an alternate channel, such as channel CH-B is regenerated and being prepared for future use. When channel CH-A reaches a point where regeneration is necessary, the flow of influent water 18 b may be switched to an alternate channel, such as channel CH-B. When operated in this latter fashion continuous conditioning activities may be conducted over a long period of time.
As further indicated in
Turning now to
As can be seen in
It is important to note that the depictions of
The inclusion of a structure such as the perforated manifold assembly 28 enables influent water the desired up-flow of influent water to be established, which is preferred for maximizing the contacting of influent water with surfaces of the molecular filtering material 64. Once the influent water 18 b passes through the molecular filtering material of the process stage, the influent water exits the process stage by way of one or more fluidic couplings 20 c, which may feed a manifold assembly similar to that of
As appreciated by skilled persons, numerous modifications may be made to the perforated manifold assembly 28. For example, additional perforations may be included, such as perforations 22 provided in input manifold 32. Further, it is contemplated that the perforations proximate to the input side 24-1 may be provided having a larger diameter than the perforations provided proximate to the output side 24-2. Yet other modifications are certainly possible and providable by skilled persons.
It should be understood that modifications may be made to the molecular filtering material 64 such that other cations and or anions may be removed from a flow 18 of influent water flowing through the water conditioning system 10 of the invention. For example, surfactants may be applied to the molecular filtering material 64 of a respective process stage. This causes an altering the electrical charge of the molecular filtering material 64, enabling anions of interest to be removed (adsorbed) from the influent. For example, one preferred surfactant that may be employed with the present invention is HDTMA-bromide or hexadeclytrimethylammonium-bromide. Yet other modifications may certainly be provided by skilled individuals.
Turning now to
At 108, influent water flows into the output finishing stage. If additional conditioning is needed, additional activities and mechanisms may be included to effect such finishing. For example, as shown in
It is important to note that the process embodiment of
Referring now to
As shown in Table 1, each included conditioning bed or process stage can be operated in one of a plurality of modes. For completeness, each of these modes will now be concisely described. The first mode listed is the conditioning (C) mode. This is the normal operating mode employed for conditioning influent water. In the C-mode valves V1, V5, and V6 may be fully or partially opened, while at minimum valves V3, V4, and V9 are closed. The remaining modes listed in Table 1 are modes associated with regeneration activities.
The first regeneration mode R1 is employed for draining a process stage such as first process stage 24 of at least a portion of the influent water present within the process stage. This water is preferably drained into either an output finishing pond, but may alternately be drained to the brine collecting and reducing pond. The actual pond to which the influent water is pumped to may be best determined based on the levels of SAR, SL and EC of the influent water present in the process stage.
The next available regeneration mode R2 provides for a loading of the process stage with chemicals employed for regenerating the load of molecular filtering material of the stage. In this mode a pre-determined volume of chemicals, possibly stored in one or more proximate chemical storage tanks, are loaded into the stage to be regenerated. It may be noted that the regeneration chemicals may be concentrated such that both modes R2 (chemical loading) and R5 (fresh water loading) may be employed for fully loading a process stage with a required regeneration solution. Cycling mode R3 may next be employed for circulating and contacting the load of molecular filtering material with the chemicals, which over a predetermined time interval will produce a heavy salt brine. Next, mode R4 may be employed for draining the salt brine into a collecting and reducing stage, such as the brine collecting and reducing pond 34 a of
It is important to note that the arrangement of valves and pumps of
As discussed hereinabove, the regeneration chemicals are applied to the molecular filtering material 64 at a time when the molecular filtering material has become saturated with sodium and other cations. As appreciated by skilled persons, the actual chemicals employed may vary with a number of parameters, including the type of molecular filtering material being employed within a respective conditioning stage. A most preferred molecular filtering material is provided as a zeolite material. Several examples, which are listed below in preference order, include:
It may be noted that the above preferred zeolites are examples of molecular filtering materials well suited for conditioning influent waters having a high sodium content, such as CBM discharge waters. When employing the above listed zeolite materials the most preferred regeneration chemicals include calcium based chemicals, such as calcium oxide (CaO), and magnesium based chemicals, such as magnesium oxide MgO). For example, when employing the preferred potassium based clinoptilolite, carbide lime may be provided in a concentrated solution that may be gravity fed from a chemical storage unit 47 into the conditioning bed 24 a to be regenerated (thereby not requiring a pump). As appreciated by skilled persons, other chemicals may be employed for regeneration purposes when specific cations present are hard to exchange with calcium and magnesium. For example, ammonia or potassium based chemicals may be employed first, and subsequently followed by one or more calcium and or magnesium based chemicals to strip and replace the ammonia or potassium cations.
Although the present invention may most preferably be configured for manual operation, wherein one or more operators manually open and close valves, as required, to effect conditioning and regenerating activities in accordance with the present invention, automated embodiments are certainly contemplated. For example, as shown in
One possible operating arrangement or sequence may call for the controller 80 to periodically determine, by way of the saturation detection module 136, when the level-of cations, as well as other possible levels of concern, of the influent water exiting the process stage reaches an upper limit (indicating a need for regeneration). That is, if it is determined that the load of molecular filtering material of the stage has become saturated, for example with sodium, soluble salts, and or other cations, the controller 80 may activate one or more electrically controlled valves of the valve and pump module 90, such as discussed hereinabove, and possibly one or more pumps, to effect a regenerating of the load of molecular filtering material of the process stage. Accordingly, the chemical storage unit 47 of
Referring now to
As skilled persons will appreciate the automated modules of
In addition, so as to not obfuscate the fundamental features and characteristics of the present invention, the depicted fluidic coupling and valving arrangements provided in the included figures have been somewhat simplified. For example, as shown in
Accordingly, while there have been described herein a plurality of the currently preferred embodiments of the present invention, along with contemplated methods of operation and use, those skilled in the art will recognize that other and further modifications may be made without departing from the invention. As such, the foregoing descriptions of the specific embodiments of the present invention have been presented for the purposes of illustration, description, and enablement. They are not intended to be exhaustive or to limit the invention to the specific forms disclosed and or illustrated. Obviously numerous modifications and alterations are possible in light of the above teachings, and it is fully intended to claim all modifications and variations that fall within the scope of the appended claims provided hereinafter.